Many providers of communication services employ a plurality of remote-access servers, such as modems, Fax handlers and voice Internet Protocol (VoIP) services connected to telephone switches. A channel router receives incoming communication requests and determines which remote-access server is to handle each incoming request. Some remote access servers are multi-channel servers which have a capacity to handle concurrently a plurality of connections up to a predetermined maximal number. In addition, some remote-access servers which are implemented mainly in software, such as the Surf Multi-access Pool (SMP) from Surf Communication Solutions Ltd., and servers 3Com, Ascend, Access, ADI, Connexent, Telogy, and Hothaus, can handle different types of connections concurrently.
When an incoming connection is received by the channel router, the router finds a remote-access server which can handle the type of the incoming connection and which is handling less than the maximal number of connections of its capacity. If no such server is found, a busy signal is returned in response to the incoming connection.
The processing power required for handling a single connection depends on the type of the connection. For example, handling a modem connection usually requires more processing power than a Fax connection, and therefore a multi-channel multi-connection-type remote access server can handle concurrently different numbers of connections according to the types of the connections. In some cases, the exact processing power needed to handle a connection is not known until the handling of the connection actually begins. In order not to overload a server beyond its capacity, existing channel routers usually assume conservative numbers for the number of channels which can be handled concurrently by a multi-channel server, for example, assuming that all the connections the server handles require a maximal processing power required by any connection. This causes waste in the usage of the multi-channel remote access servers in a multi-service system. This waste, however, provides additional assurance that the servers will be able to handle the connections they are assigned.